Tariff troubles: uncertainty persists after US Supreme Court ruling

In a landmark 6-3 decision on 20 February 2026, the US Supreme Court ruled that the International Emergency Economic Powers Act (IEEPA) did not authorise presidential tariffs, immediately eliminating all “reciprocal” and “fentanyl” tariff regimes.  

Just four days later, however, the US administration skirted the ruling by implementing a 10% temporary import duty on most goods under Section 122 of the 1974 Trade Act. US President Donald Trump has said he will raise certain countries’ tariff level to the maximum permitted rate of 15%, but has yet to follow through. 

Wood Mackenzie analysts recently took a look at what the on-again-off-again tariffs are likely to mean for the energy sector. Fill in the form to receive a complimentary extract from our insight on the topic, and read on for a short introduction. 

While the ruling delivers near-term cost relief, the volatility of US trade policy and the fact that the tariffs will expire in mid-2026 continue to create uncertainty and constrain project planning and procurement strategies. Brazil and Switzerland are major winners, seeing tariff rates plummet from 50% and 39%, respectively, to 10%. Energy products, United States-Mexico-Canada Agreement (USMCA)-compliant goods and critical minerals remain exempt, but Section 232 steel and aluminium tariffs are unchanged.  

The ruling provides moderate but uneven relief across energy supply chains, with utility project costs falling to their lowest levels since March 2025. However, the persistent Section 232 tariffs on steel and copper continue to pressure metal-intensive equipment, while looming trade actions threaten to reverse gains in renewable sectors. 

To read more about the effects of the Supreme Court tariff ruling on individual power-related sectors, fill in the form at the top of the page to receive a complimentary extract from our recent brief.